From Good Girls Scan BL:

"I shouldn't have desired you who has wings." To eat or be eaten, such is the way to live by relying on others. Kokonoe, a forest-dwelling fox, chanced upon a baby hawk that fell from his nest. He took the fledgling home as fodder, but Kokonoe ultimately couldn't bring himself to eat him, not after the child came to love him so wholeheartedly. So with that, Kokonoe named him "Yosuga" and decided to become his parent. "Please eat me." Now an adult, Yosuga always demands this of Kokonoe, wanting to repay Kokonoe for raising him so lovingly. But in response, Kokonoe starts feeling a different kind of "hunger" towards Yosuga...? "If only I could bear Kokonoe's children..."